4937CausePrint head position adjustment failed.What to DoTap OK on the touch screen to dismiss the error and retry Print head alignment following the stepsbelow.1. Print a test pattern to check the nozzles.Checking for Nozzle Clogging2. If the nozzle is blocked, clean the print head.Cleaning the Print Head3. Retry Print head alignment.Automatic Adjustment to Straighten Lines and ColorsIf any print head nozzles are still blocked, replace the print head.Replacing the Print HeadIf the error appears again, the printer may be damaged. Contact a Canon customer service center.883